As I suggested in my original post though, I have more useful things to do than look back at comments I posted years ago and compile evidence. I've moved on.
I'm sure it happens a lot more often than you realise, because in general when people get hellbanned, they come to the same realisations as me.
Not only did we never ban people for criticizing YC companies, the very first thing PG told me when I started moderating HN, and the thing that he emphasized most strongly after that, was never to do things that could be construed (or misconstrued) as censorship of anti-YC stories.
(I've edited out some irritation that leaked through in my original version of this comment.)
But it would be despicably dishonest for you guys to deny that routinely you guys do things here to protect YC companies (including manipulating voting points on comments/ submissions).
One example (on the top of my mind) is the drchrono post: https://news.ycombinator.com/item?id=7178004
Even though Skeletor made that comment like ... 20 days after the HN submission, it somehow found its way to the top. Obviously, this was through manual action. Obviously, a non-YC company is not afforded such a privilege.
Idling in #startups of freenode (unofficial HN channel), I've heard too many of these stories. The stories of rankban upon some critical comment on a YC-funded company, a slowban because of a critical comment on some YC personality, etc. etc. There are countless examples.
When these things happen one after the other, you lose trust, we cannot believe you anymore. Please stop doing this. I think the only way to win trust back at this point is if you again expose voting points at all times.
It isn't hard to deny that general impression you're reporting, because it isn't true. But I don't see any way to refute such a sweeping claim convincingly. As far as I can tell it exists only on the level of rumor and is unanswerable. But I'm happy to reply about specific cases.
In the Drchrono case, we got an email from the founder asking to post a response after the commenting window had closed. I agreed, but not because this was a YC startup, but rather because we would do this for any startup in this situation, and have indeed done so for at least one non-YC startup I can remember. Before I agreed to the Drchrono founder's request, I told him I needed to make sure that we would do it for any startup in that situation, and I thought long and hard before concluding that was true. It was by far the most important factor in that decision.
dang, I understand that you, in your position, have to be mindful of optics, you have to think of ways to say things that are best for YC. That's great, you should do that. All individuals of a company who have a public presence have to do that. The thing is, you must not focus entirely on optics -- you absolutely must in your heart have the right view. Not only because if you don't, some people will eventually find out what's up, but also because it's the right thing. Actions that favor YC companies (beyond a certain line) on a public forum such as HN are unethical. I think there have been enough things done at this point that the only way that trust can again be restored is by having more transparency -- for example, by showing comment scores at all times in some way.
You're doing an absolutely super job, probably far better than most or all of us here will ever realize simply because moderation when done properly is all but invisible so don't sweat it, this is a thing that is as far as I can see not solvable in the current set-up. Those lines were drawn long before you showed up and within those lines you're doing the best you can.
FWIW I too recall several instances of users that were banned imho unjustly as well as some threads where the pro-YC bias broke through but over the vast amount of content generated here those are very very few instances, not by far enough to claim systematic bias or to be used as evidence for some nefarious plot. More like genuine mistakes and things done in the heat of the moment. And on later reflection some of those were reverted.
(If you want I can probably dig them up for you but you're busy enough as it is.)
We want to see such comments highly ranked regardless of YC affiliation. If you post such an important update and don't get organic upvotes because the story is old, plead your case to hn@ycombinator.com.